Weak Measurement and its Experimental Realisation

Weak measurement as proposed by Aharonov, Albert and Vaidman [Phys. Rev. Lett. 60, 14 (1988)] radically changes our understanding of the measurement process and opens up new experimental possibilities for exploring quantum phenomena and the amplification of small signals. Duck et al [Phys. Rev. D, 40, 6 (1989)] gave an example of how a photon analogue of the Stern-Gerlach apparatus could be used to observe the weak measurement effect and measure the corresponding weak value. This experiment was successfully carried out by Ritchie et al [Phys. Rev. Lett. 66, 9 (1991)]. A similar experiment using non-zero mass particles is being constructed and its progress will be reported. Our future plan is to repeat the experiment of Kocsis et al [Science, 332 (2011) 1170—73], again using non-zero rest mass particles.